Cannot skip commercials while recording in progress

[faginbagin]

If you have enabled a couple of settings in the MythTV Backend web application, mythfrontend supports commercial skipping while one is watching a recording in progress. Leanfront does not. It would be great if leanfront supported this mythfrontend feature.

The settings that must be enabled in the backend web app are:
Backend Setup (MythTV Setup) -> General (General Backend Settings)
-> Job Queue (Backend-Specific) -> Allow Commercial Detection Jobs
-> Job Queue (Global) -> Start Auto Commercial Detection Jobs when the Recording Starts

I know a little bit about mythcommflag because many years ago, I made some improvements that made it into the main stream software base. If the above options are enabled, a mythcommflag instance will be started when a recording starts. The number of instances are, I believe, limited by the "Maximum Simultaneous Jobs on this Backend" setting under "Job Queue (Backend-Specific)". Mythcommflag will wait about 10 minutes and then look for a channel logo burned into the video stream. (Channel logo detection is used to assist in detecting commercials, because channel logos usually aren't present in commercials.) Then mythcommflag will start looking for commercial breaks. As they are found, they are added to the recordedmarkup table. Mythfrontend reads them (directly?) from the database when playback starts and will refresh its list periodically during playback.

I don't know if leanfront assumes an in-progress recording cannot have commercial breaks to query, or if the API support on the backend makes that assumption. What I do know is when I try to skip commercials on leanfront, after confirming I can do so on mythfrontend, I get the toast: "There is no Commercial Break or Cut List Data for this recording"

So, I don't know if its a leanfront or a backend issue. I hope it's not too hard to correct.

[bennettpeter]

This is a bug. I have code in leanfront to support this, but it is not a feature I use, so something must have gone wrong.

[bennettpeter]

When you start playback it loads the skip table. Then if the show is still recording, it schedules to reload the skip table every 3 minutes.

If you try to enable comm skip before it has found any commercials or before it has loaded them it will give that toast and not enable it. In other words it can be up to 3 minutes after the first commercial before it will allow you to enable it. Based on your description where it waits 10 minutes to look for a channel logo, you may have to wait longer for data to have been loaded.

Perhaps I should change it to allow you to enable it, just warn that no skip has been detected yet.

So if you wait for 3 minutes after the first commercial has been detected, can you enable it?

If you enable commercial skip in the settings, it should automatically be enabled when you start playback. Does that work?

Anolther case may be a recording that has finished and you run the commercial scan job while playing. Leanfront will not load the table and will not recognize it. Is this a valid case?

It uses this type of call to find the skip list

http://framework.lan:6544/Dvr/GetRecordedCommBreak?RecordedId=35

You can try running that to see if the skiplist is ready while watching. Once that has some entries and leanfront has loaded it on its 3 minute schedule, you should be able to enable them.

[faginbagin]

Before submitting this issue, I verified it was not working as you describe. I started a recording, I checked the mythcommflag logs waiting for it to get past the logo detection. I checked that mythfrontend could find and skip commercials. Only then did I start playback on leanfront and try to skip commercials.

I agree that what you describe should work. So maybe it's a mythbackend problem with the GetRecordedCommBreak API? I will check that and report back. If so, then I guess this should be a mythtv issue?

Did it ever work for you when you were implementing it in leanfront?

Could it be a regression from an earlier mythtv version? I'm running MythTV Version : v35.0+fixes.202508012334.958895d7d1~ubuntu24.04.1 and leanfront v0-557-g6692ca3

[faginbagin]

Well I was wrong. Turns out mythcommflag does NOT write to the recordedmarkup table while a recording is in progress. It uses MythCoreContext::SendMessage to send COMMFLAG_UPDATE messages to any interested listeners. I'm 99.99% sure mythfrontend is the only interested listener. So there's no way to get the commercial marks for an in progress recording using the HTTP API. My apologies.

[bennettpeter]

So all the code I added to leanfront to refresh the skip table at intervals was a waste of time. Oh well. Maybe a change to mythcommflag could fix it, so it writes to the database each time it notifies a listener. Writing or rewriting the commflag table should be very little overhead.

[faginbagin]

I'll try to look at the code and refresh my memory from 10 years ago! I can say that something is updating one record in the recordedmarkup table while a recording is in progress. I think it's for the file size. And there's something writing keyframe records to the recordedseek table. I suspect both are being done by mythbackend. Since mythtv doesn't lock tables, I wonder if there's a risk if mythcommflag tries to insert records to recordedmarkup at the same time mythbackend is updating a file size record in the same table? If that's a risk, another option might be if mythbackend listens for the COMMFLAG_UPDATE message and inserts/updates the commercial marks in recordedmarkup using the existing QT/thread locking mechanisms in mythtv? Or move the file size updating to mythcommflag?